1. Field of the Invention
The present invention generally relates to aerial ladders and particularly to an aerial ladder cradle assembly with an attachment means to allow the ladder to be deployed at a negative horizontal angle, improve operator visibility, improve compartment space, and improve leverage angle efficiency.
2. Discussion of Related Art
A common problem in aerial ladders for fire trucks is the inherent inability to deploy at a negative horizontal angle. Further, many aerial ladders have poor operator visibility and low leverage angle efficiency. There is known in the art ladders that tilt down from a horizontal position. However, none are known that use an elevated cradle. U.S Pat. No. 5,366,052 to Keh-Lin discloses a device that may be used as a conveyor in an upright position and as a ladder when lowered to the ground from that horizontal position. U.S Pat. No. 5,626,440 to Greene, Jr., et al discloses a retractable stairway that in a horizontal position that can be tilted to an extended position 45 degrees from the horizontal position. U.S. Pat. No. 4,335,803 to Sugita discloses a gangway ladder having its one end supported by a truck assembly so as to be tiltable to a horizontal or a downward position. U.S. Pat. No. 5,339,919 to Boyd discloses a boarding ladder assembly that moves the ladder from a vertical stored position to a downward position while in use.
Despite attempts in the prior art to improve range of motion of mounted ladders, none have been able to employ a cradle mount. Thus, there is a desire and a need in the art not only to increase the range of motion of a mounted aerial ladder for rescue situations, but also to improve operator visibility and improve leverage angle efficiency.